Recent advances in electronic communication, storage, and processing technology have led to an increasing demand for digital content. Today large quantities of information can be readily encoded and stored on a variety of compact and easily-transportable media, and can be conveniently accessed using high-speed connections to networks such as the Internet.
However, despite the demand for digital content, and the availability of technology that enables its efficient creation and distribution, the threat of piracy has kept the market for digital goods from reaching its full potential, for while one of the great advantages of digital technology is that it enables information to be perfectly reproduced at little cost, this is also a great threat to the rights and interests of artists, content producers, and other copyright holders who often expend substantial amounts of time and money to create original works. As a result, artists, producers, and copyright owners are often reluctant to distribute their works in electronic form—or are forced to distribute their works at inflated prices to account for piracy—thus limiting the efficiency and proliferation of the market for digital goods, both in terms of the selection of material that is available and the means by which that material is distributed.
Traditional content-distribution techniques offer little protection from piracy. Digitally-encoded songs, movies, and other forms of electronic content are typically distributed to consumers on storage media such as compact disks (CDs) or diskettes. A consumer accesses the data contained on the storage media by e.g., reading the data into the memory of a personal computer (PC) or portable device (PD). Once the data are loaded onto the PC or PD, the consumer can typically save the data to another storage medium (e.g., to the hard disk of the PC) and/or apply compression algorithms to reduce the amount of space the data occupy and the amount of time needed to transfer a copy of the data to another user's computer. Thus, the fact that electronic content is originally stored on a fixed medium such as a CD or diskette typically does little to prevent the unauthorized distribution of the content, as the content can be removed from the storage medium, duplicated, and distributed with relative ease.
Another problem faced by content owners and producers is that of protecting the integrity of their electronic content from unauthorized modification or corruption, as another characteristic of traditional forms of digital content is the ease with which it can be manipulated. For example, once information is loaded onto a user's PC from the fixed storage medium on which it was originally packaged, it can be readily modified and then saved or distributed in modified form.
While increasing attention has been paid to the development of content-management mechanisms that address the problems described above, one obstacle to the adoption of such mechanisms is the reluctance of consumers to embrace new devices or content formats that render their existing devices and content collections obsolete. Thus, there is a need for protection mechanisms that enable new decoding devices to accept previously-encoded content (or content encoded in accordance with other protection schemes), and to also enforce the preferred content protection mechanism when handling content encoded therewith. There is also a need for content protection mechanisms that allow protected content to be played on pre-existing consumer devices, while ensuring that the protection mechanisms will be enforced when protected content is played on devices that recognize the protection mechanisms.
Accordingly, there is a need for systems and methods for protecting electronic content and/or detecting unauthorized use or modification thereof. There is also a need for systems and methods that provide content producers and software and device manufacturers with the flexibility to support a specific protection scheme, but to also support pre-existing or legacy content, content encoded using other security schemes, and/or devices that are not designed to recognize the preferred protection scheme. Moreover, there is a need to accomplish these goals without materially compromising the security that the preferred protection scheme is intended to provide.